UP to 600,000 pupils will take a national curriculum test entirely on the computer within two years.
The new key stage 3 information and communications technology tests will assess pupils' ability to use websites, search engines and other computer research tools, The TES can reveal.
Pupils will not actually use the internet, however, but take advantage of a host of mock websites, spreadsheets and other resources designed specifically for the test.
The tests for 14-year-olds, which will be piloted in 81 schools next year before being launched nationwide in 2005, will initially be optional.
They offer several radical changes from current exams and will be the first mainstream school tests to be taken entirely by computer.
Schools will be free to schedule the tests whenever they want, within a month-long "window". And the technology will allow candidates to be given their test result instantly.
The tests have been developed over the past 18 months at the Qualifications and Curriculum Authority in partnership with the software company RM.
In the pilot, pupils are offered a choice of tasks, from designing a flyer for a theatre production to writing a report on a football club's finances.
While they are working, they have access to an on-screen computerised "buddy", who gives them helpful hints and tips.
When they finish, the computer automatically assesses their work. But, in another departure from current tests, the assessment is not of the quality of the pupils' final written report, but of the skills they demonstrated compiling it.
Martin Ripley, at the QCA, said: "These tests are not about looking for a right or wrong answer. We want to use the power of the computer to assess the process that a child follows when using computer technology for research.
"For example, do they go off in the direction of a spreadsheet when compiling reports? How do they go about searching for a website, what skills have they got for refining a search, and can they assess one website against another?"
He was confident that all schools would have the technology to run the tests by 2005.
They will not be compulsory by then, however. The intention is to run a "national pilot" in 2005, so any school that wants to run a test can do so.
The new tests will also be exhibited at education conferences through next term.
Ken Boston, QCA chief executive, said earlier this year that "on-screen exams clearly represent the future".